Bull. Chicago Herp. Soc. 43(10):157-164, 2008 Dialogues on the Tao* of Lachesis * Tao: “the way” in literal translation. Taoism is an ancient Chinese school of thought that advocates open mind to all possibilities, in the same way that “the uncarved block” presents itself to the sculptor. Earl Turner 1, Rob Carmichael 2 and Rodrigo Souza 3 Introduction species. For Lachesis, so far the clearly demarcated taxa, which we call species, are L. acrochorda, L. melanocephala, L. muta Deep in the Atlantic rainforest in Brazil, at the Serra Grande and L. stenophrys. Subdividing L. muta into L. m. muta and L. Center (SG), a series of chicken wire, outdoor enclosures with m. rhombeata is in taxonomic limbo and under major contro- various natural vegetation, artificial burrows/retreats and expo- versy (Ripa, 2000–2006; Fernandes et al., 2004). The present sure to the natural elements has provided Dr. Rodrigo Souza edition of the International Code of Zoological Nomenclature with the opportunity to successfully raise and breed Lachesis (Fourth Edition, ISBN 053301-006-4), however, does maintain muta rhombeata. Although seemingly “primitive” (from now trinominal nomenclature (subspecies). on PH, for Primitive Herpetoculture) by today’s highly techno- logical standards of captive care, it behooves us to consider The feeding challenge looking outside the box in terms of proper captive care of sensi- tive species like Lachesis. Whoever wishes to be successful in maintaining these pit- vipers in captivity must begin by understanding the unique The three authors come from very different backgrounds with feeding habits and the natural eco-biology involved. Well fed, respect to geography, husbandry philosophy, and facilities. healthy, stress-free animals are step one towards longevity and Looking at the ways of Taoism, however, despite our very any reproductive attempts. different backgrounds, we have been able to achieve success in working with Lachesis. It is our intention to not only show One of the inhabitants of the remaining 7% of the original some of our methods in working with bushmasters, but to also Atlantic rainforest, a little brown rice rat (Oryzomys sp.), known provide a template for working with other species and incorpo- locally as the “paca” mouse, is a bushmaster’s favorite in the rating field studies and observations with captive care. wild. The average weight of these wild rodents and of four other rodent species that Rod has captured in prime Lachesis Rob Carmichael serves as Curator of the Wildlife Discovery territory is around 90 g (-3 oz) or less. That makes us think that Center (WDC) in Lake Forest, Illinois, where the bushmaster is in nature Lachesis is very active (at night) and is constantly displayed in a semi-naturalistic exhibit utilizing both modern- moving around searching for “light” meals (90 g), and most day herpetoculture methods and the integration of observations likely feeds more than once a week. The fit and strong individu- made from the more “primitive” way. als we’ve all met in the wild are the living proof of it. Heavier Dr. Earl Turner comes from a zoo background in the Texas prey items are offered to them in shady Serra Grande --- every area where he has kept and bred various Lachesis by utilizing eight days if it’s “cold” (20–24EC / 68–75.2EF), or every fifteen modern day advances in technology under controlled, indoor days if its sunny (24–28EC / 75.2–82.4EF). Bushmasters are conditions (Turner, 1997, 1998). extremely selective when it comes to feeding, and unlike in the sympatric Bothrops genus, even animals in the 2.4 m (-8 ft) So what method is best? The (apparently) “primitive,” au total length (TL) range will not usually try to strike-hold any naturale (but not naive) way, or utilizing today’s technology to prey weighing over 220 g (-8 oz). As a comparison so that we re-create natural conditions in a controlled, indoor setting? may comprehend how specialized these animals are, a large BOTH! We will be sharing our experiences, our failures, our Brazilian Bothrops like B. jararacussu (1.8 m or -6 ft TL) can passion and our sincere desire to share everything we consider easily ingest a 400 g (-14 oz) rat or guinea pig. relevant to help others avoid the many problems we’ve faced while dealing with the Lachesis clan, with special emphasis on One of the wonderful benefits of today’s internet is the Lachesis muta rhombeata, L. m. muta and L. stenophrys. ability to network and converse with other professionals. After a brief discussion via email with the other two authors, the The maintaining of the subspecific status in this paper is not keepers at WDC realized that they were offering prey too large a personal stand for or against anyone. It means in Rod’s case for a Lachesis muta that had just arrived at their facility. After that he is specifically referring to Lachesis from the Atlantic many unsuccessful offerings, they decided to offer an adult rainforest, from the Brazilian east (Atlantic) coast. It’s neces- mouse to the 5-ft male L. muta. Needless to say, they had a sary however to remember that many authorities are not very happy ending. enthusiastic about subspecies in herpetology, because often it seems that they were established based on superficial attention Bushmasters will strike-hold in the shoulder area any living to one or a very few characteristics --- and at least sometimes, if prey (mostly mammals, occasionally birds) weighing up to 120 g we look at another character we would establish different sub- (-4 oz), basically what the snake will find in nature, and will 1. 21 N. Sunset Drive, Kerrville TX 78028. [email protected] 2. Wildlife Discovery Center at Elawa Farm, 1401 Middlefork Drive, Lake Forest IL 60045. [email protected] 3. Serra Grande Center for Lachesis muta Breeding, Caixa Postal 05, Itacaré, Bahia 45.530.000, BRAZIL. [email protected] 157 usually strike-release and conduct chemosensory search and The length that these snakes may reach is a very controver- trail-following (a hard and frequently unsuccessful task in the sial issue. They are the largest venomous snakes of the Ameri- flooded rainforest) if the prey weighs over 120 g. Large prey cas (second in the world only to king cobras). Bushmasters reaction to strike-hold could be dangerous to the snake: 220 g beyond 300 cm TL are rare, and Ditmars’ (1910) L. stenophrys (-8 oz) is the heaviest prey item we suggest one should offer to at 350–360 cm TL remains as the longest specimen. adult individuals. Ideal prey size in Serra Grande was learned In 1957 a DC-3/C-47 delivered a large box flown from the hard way, through mistakes that have resulted in regurgita- Colombia to the U.S. by the Tarpon Zoo of Tarpon Springs, tion and esophagus injury, that sometimes led to death. Once Florida. When it was opened, all that could be heard were again, we can take some of these in situ and field observations words of astonishment by Fred Penman, Trudie Jerkins and Dr. and translate them into our own captive management programs Earl Turner, as out crawled the biggest bushmaster they all have in dealing with Lachesis. By taking note of the mistakes made seen to this day. Immediately a string was laid as closely as in the past, we can make improvements in order to prevent possible next to this snake. After the operation was completed a future problems, that usually start with the offering of oversized few times, the string measurement was 12 ft, 1 in. Allowing for rats, in a hot enclosure (more than 28EC or 82.4EF). Knowledge several factors, they all agreed that the snake was (at least) 11 ft, is power, and this knowledge about bushmasters’ feeding prefer- 3 in, give or take an inch. At approximately 342.9 cm TL, this ences in the Atlantic rainforest was achieved by interviewing snake is probably among the three longest bushmasters ever native people (mostly hunters and woodsmen), and by placing (reliably) measured. mousetraps in different crops. This was the starting point of Nucleo Serra Grande 7 years ago, when we started efforts to So, with such a huge digestive tube and the low temperatures control the slaughter perpetrated against these snakes (by safely (and low metabolism rates) of the natural habitat, small prey removing individuals found in roads, crops or residential areas), preference may be taken as an evolutionary adaptation (Ripa, labeled as “Vulnerable” by the International Union for the 2000–2006) to cold environment (slow digestion). Oversized Conservation of Nature. food items could turn into putrid gas bombs inside the animal, halfway into the intestine (incomplete digestion), often killing The picture below shows the true bushmaster strike-hold the snake if it’s too late for vomiting it. The proteolytic action approach, always in the shoulder area, with venom injected of the Lachesis venom is not remarkably strong and it does not directly in heart and lungs, causing “instant” death. These help digestion as much as Bothrops venom does, for instance. observations, strike-hold or trail following (chemosensory For this reason, bushmasters are never seen basking in the sun search) according to size of the prey, confirm those of Chiszar et after eating, thus accelerating general metabolism, something al. (1989) and Boyer et al. (1995). that Bothrops always does. If the average temperature in the enclosure is above 28EC (82.4EF), keepers will probably experi- A very special need ence a high rate of regurgitation and its hazards to the health of A cool temperature by tropical standards of 16.6EC (61.8EF) the animals.